Phosphate tightly associated with protein has been known since the late nineteenth century. Since then, a variety of covalent linkages of phosphate to proteins have been found. The most common involve esterification of phosphate to serine, threonine, and tyrosine with smaller amounts being linked to lysine, arginine, histidine, aspartic acid, glutamic acid, and cysteine. The occurrence of phosphorylated proteins implies the existence of one or more protein kinases capable of phosphorylating amino acid residues on proteins, and also of protein phosphatases capable of hydrolyzing phosphorylated amino acid residues on proteins.
Protein kinases play critical roles in the regulation of biochemical and morphological changes associated with cellular growth and division (D""Urso, G. et al. (1990) Science 250: 786-791; Birchmeier. C. et al. (1993) Bioessays 15: 185-189). They serve as growth factor receptors and signal transducers and have been implicated in cellular transformation and malignancy (Hunter, T. et al. (1992) Cell 70: 375-387; Posada, J. et al. (1992) Mol. Biol. Cell 3: 583-592; Hunter, T. et al. (1994) Cell 79: 573-582). For example, protein kinases have been shown to participate in the transmission of signals from growth-factor receptors (Sturgill, T. W. et al. (1988) Nature 344: 715-718; Gomez, N. et al. (1991) Nature 353: 170-173), control of entry of cells into mitosis (Nurse, P. (1990) Nature 344: 503-508; Maller, J. L. (1991) Curr. Opin. Cell Biol. 3: 269-275) and regulation of actin bundling (Husain-Chishti, A. et al. (1988) Nature 334: 718-721). Protein kinases can be divided into two main groups based on either amino acid sequence similarity or specificity for either serine/threonine or tyrosine residues. A small number of dual-specificity kinases are structurally like the serine/threonine-specific group. Within the broad classification, kinases can be further sub-divided into families whose members share a higher degree of catalytic domain amino acid sequence identity and also have similar biochemical properties. Most protein kinase family members also share structural features outside the kinase domain that reflect their particular cellular roles. These include regulatory domains that control kinase activity or interaction with other proteins (Hanks, S. K. et al. (1988) Science 241: 42-52). For example, kinases which contain ankyrin repeat domains have been identified, such as the Integrin-linked kinase (ILK).
ILK is an ankyrin repeat containing serine-threonine protein kinase which interacts with integrin xcex21 and xcex23 heterodimeric transmembrane glycoprotein subunit cytoplasmic domains. Integrins communicate with cell surface and cytoplasmic molecules such as cytoskeletal and catalytic signaling proteins (Hannigan G. E. et al. (1981) Nature 379:91-96, Schwartz M. A. et al. (1995) Annu. Rev. Cell Dev. Biol. 11:549-599). Overexpression of ILK increases the expression of cyclin A, cyclin D1 and Cdk4 proteins by overriding the adhesion-dependent regulation of cell cycle progression through G1 into S phase. This activity suggests that ILK may be an important regulator of integrin-mediated cell cycle progression (Radeva G. et al. (1997) J. Biol. Chem. 272:13937-13944). Overexpression of ILK also stimulates fibronectin matrix assembly in epithelial cells (Wu C. et al. (1998) J. Biol. Chem. 273:528-536).
The present invention is based, at least in part, on the discovery of novel ankyrin repeat containing kinases, referred herein as xe2x80x9cCardiac-related Ankyrin-Repeat Protein Kinasexe2x80x9d (xe2x80x9cCARKxe2x80x9d) nucleic acid and protein molecules. The CARK molecules of the present invention are useful as modulating agents for regulating a variety of cellular processes, e.g., cardiac cellular processes. Accordingly, in one aspect, this invention provides isolated nucleic acid molecules encoding CARK proteins or biologically active portions thereof, as well as nucleic acid fragments suitable as primers or hybridization probes for the detection of CARK-encoding nucleic acids.
In one embodiment, a CARK nucleic acid molecule of the invention is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or more identical to the nucleotide sequence (e.g., to the entire length of the nucleotide sequence) shown in SEQ ID NO:1 or 3 or the nucleotide sequence of the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530, or a complement thereof.
In one embodiment, a CARK nucleic acid molecule of the invention is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 82%, 85%, 90%, 95%, 98%, or more identical to the nucleotide sequence (e.g., to the entire length of the nucleotide sequence) shown in SEQ ID NO:7 or 9 or the nucleotide sequence of the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530, or a complement thereof.
In a preferred embodiment, the isolated nucleic acid molecule includes the nucleotide sequence shown SEQ ID NO:1 or 3, or a complement thereof. In another embodiment, the nucleic acid molecule includes SEQ ID NO:3 and nucleotides 1-47 of SEQ ID NO:1. In another embodiment, the nucleic acid molecule includes SEQ ID NO:3 and nucleotides 2553-3025 of SEQ ID NO:1. In another preferred embodiment, the nucleic acid molecule consists of the nucleotide sequence shown in SEQ ID NO:1 or 3. In another preferred embodiment, the nucleic acid molecule includes a fragment of at least 350, 467, 762, 918, 1236, or 1275 nucleotides (e.g., contiguous nucleotides) of the nucleotide sequence of SEQ ID NO:1 or 3, or a complement thereof.
In a preferred embodiment, the isolated nucleic acid molecule includes the nucleotide sequence shown SEQ ID NO:7 or 9, or a complement thereof. In another embodiment, the nucleic acid molecule includes SEQ ID NO:9 and nucleotides 1-60 of SEQ ID NO:7. In another embodiment, the nucleic acid molecule includes SEQ ID NO:9 and nucleotides 2566-3026 of SEQ ID NO:7. In another preferred embodiment, the nucleic acid molecule consists of the nucleotide sequence shown in SEQ ID NO:7 or 9. In another preferred embodiment, the nucleic acid molecule includes a fragment of at least 2962 nucleotides (e.g., 2962 contiguous nucleotides) of the nucleotide sequence of SEQ ID NO:7 or 9, or a complement thereof. In another embodiment, a CARK nucleic acid molecule includes a nucleotide sequence encoding a protein having an amino acid sequence sufficiently homologous to the amino acid sequence of SEQ ID NO:2 or 8, or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In a preferred embodiment, a CARK nucleic acid molecule includes a nucleotide sequence encoding a protein having an amino acid sequence at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or more homologous to the entire length of the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In another preferred embodiment, a CARK nucleic acid molecule includes a nucleotide sequence encoding a protein having an amino acid sequence at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the entire length of the amino acid sequence of SEQ ID NO:8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530.
In another preferred embodiment, an isolated nucleic acid molecule encodes the amino acid sequence of human CARK. In yet another preferred embodiment, the nucleic acid molecule includes a nucleotide sequence encoding a protein having the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In yet another preferred embodiment, the nucleic acid molecule is at least 350, 467, 762, 918, 1236, or 1275 nucleotides in length. In a further preferred embodiment, the nucleic acid molecule is at least 350, 467, 762, 918, 1236, or 1275 nucleotides in length and encodes a protein having a CARK activity (as described herein).
In another preferred embodiment, an isolated nucleic acid molecule encodes the amino acid sequence of rat CARK. In yet another preferred embodiment, the nucleic acid molecule includes a nucleotide sequence encoding a protein having the amino acid sequence of SEQ ID NO:8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In yet another preferred embodiment, the nucleic acid molecule is at least 2962 nucleotides in length. In a further preferred embodiment, the nucleic acid molecule is at least 2962 nucleotides in length and encodes a protein having a CARK activity (as described herein).
Another embodiment of the invention features nucleic acid molecules, preferably CARK nucleic acid molecules, which specifically detect CARK nucleic acid molecules relative to nucleic acid molecules encoding non-CARK proteins. For example, in one embodiment, such a nucleic acid molecule is at least 250-300, 300-335, 339, 339-350, 350-400, 400-450, 467, 467-500, 500-550, or 550-600, 600-750, 762, 762-800, 800-900, 918, 918-1000, 1000-1200, 1236, 1275, 1275-1400, 1400-1600, 1600-1800, 1800-2000, 2000-2400, 2400-2800, 2800-2900, 2962, or more nucleotides in length and hybridizes under stringent conditions to a nucleic acid molecule comprising the nucleotide sequence shown in SEQ ID NO:1, 3, 7, or 9, or, the nucleotide sequence of the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530, or a complement thereof.
In preferred embodiments, the nucleic acid molecules are at least 15 (e.g., contiguous) nucleotides in length and hybridize under stringent conditions to nucleotides 1-47, 94-294, 318-338, 1145-1364, 1833-1921, 2051-2267, 2290-2543, or 3018-3025 of SEQ ID NO:1. In other preferred embodiments, the nucleic acid molecules comprise nucleotides 1-47, 94-294, 318-338, 1145-1364, 1833-1921, 2051-2267, 2290-2543, or 3018-3025 of SEQ ID NO:1. In other preferred embodiments, the nucleic acid molecules consist of nucleotides 1-47, 94-294, 318-338, 1145-1364, 1833-1921, 2051-2267, 2290-2543, or 3018-3025 of SEQ ID NO:1.
In other preferred embodiments, the nucleic acid molecule encodes a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:2 or 8, or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO:1 or 3, or SEQ ID NO:7 or 9, respectively, under stringent conditions.
Another embodiment of the invention provides an isolated nucleic acid molecule which is antisense to a CARK nucleic acid molecule, e.g., the coding strand of a CARK nucleic acid molecule.
Another aspect of the invention provides a vector comprising a CARK nucleic acid molecule. In certain embodiments, the vector is a recombinant expression vector. In another embodiment, the invention provides a host cell containing a vector of the invention. In yet another embodiment, the invention provides a host cell containing a nucleic acid molecule of the invention. The invention also provides a method for producing a protein, preferably a CARK protein, by culturing in a suitable medium, a host cell, e.g., a mammalian host cell such as a non-human mammalian cell, of the invention containing a recombinant expression vector, such that the protein is produced.
Another aspect of this invention features isolated or recombinant CARK proteins and polypeptides. In one embodiment, the isolated protein, preferably a CARK protein, includes at least one ankyrin repeat domain, and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains. In another embodiment, the isolated protein, preferably a CARK protein, includes at least one protein kinase domain. In a preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains, and has an amino acid sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the amino acid sequence of SEQ ID NO:2 or 8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In another preferred embodiment, the protein, preferably a CARK protein, includes at least one protein kinase domain and has an amino acid sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the amino acid sequence of SEQ ID NO:2 or 8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In another preferred embodiment, the protein, preferably a CARK protein, includes at least one LXCXE motif and has an amino acid sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the amino acid sequence of SEQ ID NO:2 or 8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In yet another preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains, at least one protein kinase domain, and has an amino acid sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the amino acid sequence of SEQ ID NO:2 or 8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530. In a preferred embodiment, a CARK protein includes at least one or more of the following domains and/or motifs: an ankyrin repeat domain, a kinase domain or a LXCXE motif, and has an amino acid sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98% or more homologous to the amino acid sequence of SEQ ID NO:2 or 8, or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number PTA-1530.
In another preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankynn repeat domains and has a CARK activity, as described herein. In yet another preferred embodiment, the protein, preferably a CARK protein, includes a protein kinase domain and has a CARK activity, as described herein. In another preferred embodiment, the protein, preferably a CARK protein, includes a LXCXE motif and has a CARK activity, as described herein. In a further preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains, at least one protein kinase domain, and has a CARK activity, as described herein. In a preferred embodiment, a CARK protein includes at least one or more of the following domains and/or motifs: an ankyrin repeat domain, a kinase domain or a LXCXE motif, and has a CARK activity, as described herein. In yet another preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains and is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9. In a further embodiment, the protein, preferably a CARK protein, includes at least one protein kinase domain and is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9. In a further embodiment, the protein, preferably a CARK protein, includes at least one LXCXE motif and is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9. In another preferred embodiment, the protein, preferably a CARK protein, includes at least one ankyrin repeat domain and preferably two, three, four, five, six, seven, eight, or, most preferably, nine or more ankyrin repeat domains, at least one protein kinase domain, and is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9. In a preferred embodiment, a CARK protein includes at least one or more of the following domains and/or motifs: an ankyrin repeat domain, a kinase domain or a LXCXE motif, and is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9.
In another embodiment, the invention features fragments of the protein having the amino acid sequence of SEQ ID NO:2 or 8, wherein the fragment comprises at least 15 amino acids (e.g., contiguous amino acids) of the amino acid sequence of SEQ ID NO:2 or 8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with the ATCC as Accession Number PTA-1530. In one embodiment, the protein comprises amino acid residues 463 to 716 of SEQ ID NO:2 or 8. In another embodiment, the invention comprises amino acid residues 411-415 of SEQ ID NO:2 or 8. In yet another embodiment, the protein, preferably a CARK protein, has the amino acid sequence of SEQ ID NO:2 or 8.
In another embodiment, the invention features an isolated protein, preferably a CARK protein, which is encoded by a nucleic acid molecule consisting of a nucleotide sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 82%, 85%, 90%, 95%, 98% or more homologous to a nucleotide sequence of SEQ ID NO:1, 3, 7, or 9, or a complement thereof. This invention further features an isolated protein, preferably a CARK protein, which is encoded by a nucleic acid molecule consisting of a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1, 3, 7, or 9, or a complement thereof.
The proteins of the present invention or portions thereof, e.g., biologically active portions thereof, can be operatively linked to a non-CARK polypeptide (e.g., heterologous amino acid sequences) to form fusion proteins. The invention further features antibodies, such as monoclonal or polyclonal antibodies, that specifically bind proteins of the invention, preferably CARK proteins. In addition, the CARK proteins or biologically active portions thereof can be incorporated into pharmaceutical compositions, which optionally include pharmaceutically acceptable carriers.
In another aspect, the present invention provides a method for detecting the presence of a CARK nucleic acid molecule, protein or polypeptide in a biological sample by contacting the biological sample with an agent capable of detecting a CARK nucleic acid molecule, protein or polypeptide such that the presence of a CARK nucleic acid molecule, protein or polypeptide is detected in the biological sample.
In another aspect, the present invention provides a method for detecting the presence of CARK activity in a biological sample by contacting the biological sample with an agent capable of detecting an indicator of CARK activity such that the presence of CARK activity is detected in the biological sample.
In another aspect, the invention provides a method for modulating CARK activity comprising contacting a cell capable of expressing CARK with an agent that modulates CARK activity such that CARK activity in the cell is modulated. In one embodiment, the agent inhibits CARK activity. In another embodiment, the agent stimulates CARK activity. In one embodiment, the agent is an antibody that specifically binds to a CARK protein. In another embodiment, the agent modulates expression of CARK by modulating transcription of a CARK gene or translation of a CARK mRNA. In yet another embodiment, the agent is a nucleic acid molecule having a nucleotide sequence that is antisense to the coding strand of a CARK mRNA or a CARK gene.
In one embodiment, the methods of the present invention are used to treat a subject having a disorder characterized by aberrant or unwanted CARK protein or nucleic acid expression or activity by administering an agent which is a CARK modulator to the subject. In one embodiment, the CARK modulator is a CARK protein. In another embodiment the CARK modulator is a CARK nucleic acid molecule. In yet another embodiment, the CARK modulator is a peptide, peptidomimetic, or other small molecule. In a preferred embodiment, the disorder characterized by aberrant or unwanted CARK protein or nucleic acid expression is a cardiovascular disorder.
The present invention also provides a diagnostic assay for identifying the presence or absence of a genetic alteration characterized by at least one of (i) aberrant modification or mutation of a gene encoding a CARK protein; (ii) mis-regulation of the gene; and (iii) aberrant post-translational modification of a CARK protein, wherein a wild-type form of the gene encodes a protein with a CARK activity.
In another aspect the invention provides a method for identifying a compound that binds to or modulates the activity of a CARK protein, by providing an indicator composition comprising a CARK protein having CARK activity, contacting the indicator composition with a test compound, and determining the effect of the test compound on CARK activity in the indicator composition to identify a compound that modulates the activity of a CARK protein.
Other features and advantages of the invention will be apparent from the following detailed description and claims.